Detection of Mycobacterium tuberculosis complex DNA in CD34-positive peripheral blood mononuclear cells of asymptomatic tuberculosis contacts: an observational study.

BACKGROUND: Haematopoietic stem cells expressing the CD34 surface marker have been posited as a niche for Mycobacterium tuberculosis complex bacilli during latent tuberculosis infection. Our aim was to determine whether M tuberculosis complex DNA is detectable in CD34-positive peripheral blood mononuclear cells (PBMCs) isolated from asymptomatic adults living in a setting with a high tuberculosis burden. METHODS: We did a cross-sectional study in Ethiopia between Nov 22, 2017, and Jan 10, 2019. Digital PCR (dPCR) was used to determine whether M tuberculosis complex DNA was detectable in PBMCs isolated from 100 mL blood taken from asymptomatic adults with HIV infection or a history of recent household or occupational exposure to an index case of human or bovine tuberculosis. Participants were recruited from HIV clinics, tuberculosis clinics, and cattle farms in and around Addis Ababa. A nested prospective study was done in a subset of HIV-infected individuals to evaluate whether administration of isoniazid preventive therapy was effective in clearing M tuberculosis complex DNA from PBMCs. Follow-up was done between July 20, 2018, and Feb 13, 2019. QuantiFERON-TB Gold assays were also done on all baseline and follow-up samples. FINDINGS: Valid dPCR data (ie, droplet counts >10 000 per well) were available for paired CD34-positive and CD34-negative PBMC fractions from 197 (70%) of 284 participants who contributed data to cross-sectional analyses. M tuberculosis complex DNA was detected in PBMCs of 156 of 197 participants with valid dPCR data (79%, 95% CI 74-85). It was more commonly present in CD34-positive than in CD34-negative fractions (154 [73%] of 197 vs 46 [23%] of 197; p<0·0001). Prevalence of dPCR-detected M tuberculosis complex DNA did not differ between QuantiFERON-negative and QuantiFERON-positive participants (77 [78%] of 99 vs 79 [81%] of 98; p=0·73), but it was higher in HIV-infected than in HIV-uninfected participants (67 [89%] of 75 vs 89 [73%] of 122, p=0·0065). By contrast, the proportion of QuantiFERON-positive participants was lower in HIV-infected than in HIV-uninfected participants (25 [33%] of 75 vs 73 [60%] of 122; p<0·0001). Administration of isoniazid preventive therapy reduced the prevalence of dPCR-detected M tuberculosis complex DNA from 41 (95%) of 43 HIV-infected individuals at baseline to 23 (53%) of 43 after treatment (p<0·0001), but it did not affect the prevalence of QuantiFERON positivity (17 [40%] of 43 at baseline vs 13 [30%] of 43 after treatment; p=0·13). INTERPRETATION: We report a novel molecular microbiological biomarker of latent tuberculosis infection with properties that are distinct from those of a commercial interferon-γ release assay. Our findings implicate the bone marrow as a niche for M tuberculosis in latently infected individuals. Detection of M tuberculosis complex DNA in PBMCs has potential applications in the diagnosis of latent tuberculosis infection, in monitoring response to preventive therapy, and as an outcome measure in clinical trials of interventions to prevent or treat latent tuberculosis infection. FUNDING: UK Medical Research Council.

Epidemiology of Bovine Tuberculosis and Its Zoonotic Implication in Addis Ababa Milkshed, Central Ethiopia.

Bovine tuberculosis (bTB) continues to be one of the most widely distributed chronic infectious diseases of zoonotic importance, which causes a significant economic loss in animal production. A cross-sectional study was conducted to estimate the prevalence of bTB and its associated risk factors and type the Mycobacterium bovis isolated in central Ethiopia. A total of 65 dairy farms and 654 cattle were tested for bTB using a single intradermal comparative cervical tuberculin (SICCT) test. Data on farm management, animal-related characteristics, and the owner's knowledge of the zoonotic importance of bTB were collected using a structured questionnaire. In addition, a total of 16 animals from different farms were identified for postmortem examination. Lowenstein Jensen (LJ) culture was also conducted, and spoligotyping was used to type the M. bovis strains isolated. Chi-square test and logistic regression models were used to analyze the herd- and animal-level risk factors. Herd- and animal-level prevalence rates of bTB were 58.5% (95% CI: 46.2%-69.2%) and 39.3% (95% CI: 35.5%-43.5%), respectively. At the herd level, poor farm management was the predictor for bTB positivity (p < 0.05). Animal breed, poor BCS, farm type, and poor farm management conditions were significant predictors of bTB positivity (p < 0.05) at an individual animal level. All animals identified for postmortem examination were found to have gross TB-like lesions. A total of 14 M. bovis strains were identified from 12 animals that were positive for LJ culture. The strain with the largest number of clusters (five isolates) was SB1176, followed by SB0134 (three isolates), SB0192 (two isolates), and SB2233 (two isolates), and two new strains, each consisting of only one isolate. The majority (58.5%) of the respondents did not know the zoonotic importance of bTB. The result of this study showed a high prevalence of bTB in the Addis Ababa milkshed and a low level of consciousness of the owners on its transmission to humans. Therefore, the launching of acceptable control measures of bTB and the creation of public awareness about its zoonotic transmission and prevention measures are required.

Cellular and Cytokine Responses in the Granulomas of Asymptomatic Cattle Naturally Infected with Mycobacterium bovis in Ethiopia.

Cell (CD3+ T cell and CD68+ macrophages), cytokine (interferon gamma-positive [IFN-γ+] and tumor necrosis factor alpha-positive [TNF-α+]), and effector molecule (inducible nitric oxide synthase-positive [iNOS+]) responses were evaluated in the lymph nodes and tissues of cattle naturally infected with Mycobacterium bovis Detailed postmortem and immunohistochemical examinations of lesions were performed on 16 cows that were positive by the single intradermal cervical comparative tuberculin (SICCT) test and that were identified from dairy farms located around the city of Addis Ababa, Ethiopia. The severity of the gross lesion was significantly higher (P = 0.003) in M. bovis culture-positive cows (n = 12) than in culture-negative cows (n = 4). Immunohistochemical techniques showed that in culture-positive cows, the mean immunolabeling fraction of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV (P < 0.001). In contrast, the CD68+ macrophage, IFN-γ+, TNF-α+, and iNOS+ immunolabeling fractions increased from stage I to stage IV (P < 0.001). In the early stages, culture-negative cows showed a significantly higher fraction of CD68+ macrophage (P = 0.03) and iNOS+ (P = 0.007) immunolabeling fractions than culture-positive cows. Similarly, at advanced granuloma stages, culture-negative cows demonstrated significantly higher mean proportions of CD3+ T cells (P < 0.001) than culture-positive cows. Thus, this study demonstrates that, following natural infection of cows with M. bovis, as the stage of granuloma increases from stage I to stage IV, the immunolabeling fraction of CD3+ cells decreases, while the CD68+ macrophage, IFN-γ+, TNF-α+, and iNOS+ immunolabeling fractions increases.

Anatomic and Cellular Niches for Mycobacterium tuberculosis in Latent Tuberculosis Infection.

Latent tuberculosis has been recognized for over a century, but discovery of new niches, where Mycobacterium tuberculosis resides, continues. We evaluated literature on M.tuberculosis locations during latency, highlighting that mesenchymal and hematopoietic stem cells harbor organisms in sensitized asymptomatic individuals.

High-dose vitamin D3 in the treatment of severe acute malnutrition: a multicenter double-blind randomized controlled trial.

Background: Vitamin D deficiency is common in children with severe acute malnutrition, in whom it is associated with severe wasting. Ready-to-use therapeutic food (the standard treatment) contains modest amounts of vitamin D that do not reliably correct deficiency. Objective: The aim of this study was to determine whether high-dose oral vitamin D3 enhances weight gain and development in children with uncomplicated severe acute malnutrition. Design: We conducted a randomized placebo-controlled trial of high-dose vitamin D3 supplementation in children aged 6-58 mo with uncomplicated severe acute malnutrition in Pakistan. Participants were randomly assigned to receive 2 oral doses of 200,000 IU vitamin D3 or placebo at 2 and 4 wk after starting ready-to-use therapeutic food. The primary outcome was the proportion of participants gaining >15% of baseline weight at 8 wk after starting ready-to-use therapeutic food (the end of the study). Secondary outcomes were mean weight-for-height or -length z score and the proportion of participants with delayed development at the end of the study (assessed with the Denver Development Screening Tool II), adjusted for baseline values. Results: Of the 194 randomly assigned children who started the study, 185 completed the follow-up and were included in the analysis (93 assigned to intervention, 92 to control). High-dose vitamin D3 did not influence the proportion of children gaining >15% of baseline weight at the end of the study (RR: 1.04; 95% CI: 0.94,1.15, P = 0.47), but it did increase the weight-for-height or -length z score (adjusted mean difference: 1.07; 95% CI: 0.49,1.65, P < 0.001) and reduce the proportion of participants with delayed global development [adjusted RR (aRR): 0.49; 95% CI: 0.31, 0.77, P = 0.002], delayed gross motor development (aRR: 0.29; 95% CI: 0.13, 0.64, P = 0.002), delayed fine motor development (aRR: 0.59; 95% CI: 0.38, 0.91, P = 0.018), and delayed language development (aRR: 0.57; 95% CI: 0.34, 0.96, P = 0.036). Conclusions: High-dose vitamin D3 improved the mean weight-for-height or -length z score and developmental indexes in children receiving standard therapy for uncomplicated severe acute malnutrition in Pakistan. This trial was registered at clinicaltrials.gov as NCT03170479.

IgA and IgG against Mycobacterium tuberculosis Rv2031 discriminate between pulmonary tuberculosis patients, Mycobacterium tuberculosis-infected and non-infected individuals.

As part of a major project to investigate protective and diagnostic immune markers against tuberculosis (TB), we measured antibody isotype responses to Mycobacterium tuberculosis (Mtb) antigens (LAM, Rv2031, and HBHA) in cohorts of 149 pulmonary tuberculosis patients (PTBP), 148 household contacts (HHCs), and 68 community controls (CCs) in an endemic setting. ELISA was used to measure levels of IgA, IgG, and IgM from sera of cohorts at baseline, and at 6 and 12 months from entry. The results show that there were significant differences in IgA, IgG, and IgM responses to the different antigens and in the three cohorts. At baseline, the level of IgM against RV2031 and LAM did not vary between cohorts, but the levels of IgA and IgG against Rv2031 were significantly higher in PTB patients than HHCs and CCs, followed by HHCs, and the lowest in CCs. In patients, there was a significant variation in antibody responses before and after chemotherapy. The levels of IgA and IgG against HBHA, and IgA against Rv2031 decreased significantly and remained low, while IgA and IgG against LAM increased significantly and remained high following chemotherapy. However, the levels of IgM against Rv2031 and LAM increased at 6 months but decreased again at 12 months. IgM against HBHA did not show any significant variation before and after chemotherapy. Similarly, there were also significant variations in antibody responses in HHCs over time. Our results show that there are significant variations in IgA, IgG and IgM responses to the different antigens and in the three cohorts, implying that not all antibody isotype responses are markers of clinical TB. In addition, the current and previous studies consistently show that IgA and IgG against Rv2031 discriminate between clinical disease, Mtb-infected and non-infected individuals.

IFN-γ against the 38-kDa antigen of Mycobacterium tuberculosis discriminates pulmonary tuberculosis from infection and infection from exposure: evidence from a study of human population in a high endemic setting.

Mycobacterium tuberculosis (Mtb) 38-kDa antigen is an immunogenic lipoprotein that induces strong T-cell responses in experimental animals. However, there is limited information on the role of this antigen in human population. In this article, we present the dynamics of pro-inflammatory (IFN-γ and TNF-α) and anti-inflammatory cytokine (IL-10) against the 38 kDa in cohorts of pulmonary TB (PTB) patients, household contacts (HHCs), and community controls (CCs) in a high endemic setting. Whole blood assay was used to determine the levels of cytokines in 149 patients, 149 HHCs, and 68 CCs at baseline, 6 months, and 12 months. At baseline, the level of IFN-γ was significantly (p < 0.0001) higher in CCs and HHCs than in untreated patients. CCs had significantly (p < 0.05) higher level of IFN-γ than HHCs. There was no significant difference between treated and untreated patients, and there was no significant change in HHCs over 12 months. At baseline, the levels of IL-10 and TNF-α were significantly (p < 0.0001) higher in patients than in HHCs and CCs. No significant change was observed between treated patients and untreated patients and HHCs over time. The study shows that IFN-γ against the 38 kDa discriminates clinical TB from infection and infection from exposure, suggesting its potential for immune protection and diagnosis.

IFN-γ and IgA against non-methylated heparin-binding hemagglutinin as markers of protective immunity and latent tuberculosis: Results of a longitudinal study from an endemic setting.

BACKGROUND: Heparin-binding hemagglutinin (HBHA) is a surface protein involved in epithelial attachment and extrapulmonary dissemination of Mycobacterium tuberculosis. HBHA is attracting increasing attention for its vaccine and diagnostic potential. In a longitudinal study, we investigated non-methylated, recombinant HBHA-specific cytokine and antibody profiles in cohorts of TB patients, their contacts and community controls in an endemic setting. METHODS: Whole blood assay was done at baseline, 6 and 12 months in patients and contacts, and at entry in controls. ELISA was used to measure IFN-γ, TNF-α and IL-10 (from supernatants), and IgG, IgM and IgA (from sera). RESULTS: Fifty-three percent of controls and 72.1% of contacts were QFT-GIT positive. Baseline IFN-γ was significantly higher in community controls and contacts compared to untreated TB patients (p < 0.0001). Controls had significantly higher IgA and lower IgM compared to both untreated TB patients and contacts (p < 0.0001). IL-10 was significantly higher in untreated TB patients compared to contacts and controls (p < 0.0001). In treated TB patients, IFN-γ significantly increased (p < 0.0001) whereas IL-10 significantly decreased (p < 0.001). CONCLUSION: This study reports for the first time that anti-HBHA IgA could have the potential as a biomarker of protective immunity. In addition, non-methylated, recombinant HBHA-induced IFN-γ could be used as a biomarker of protective immunity and latent TB.

Prevalence of tuberculosis, HIV, and TB-HIV co-infection among pulmonary tuberculosis suspects in a predominantly pastoralist area, northeast Ethiopia.

BACKGROUND: TB-HIV co-infection is one of the biggest public health challenges in sub-Saharan Africa. Although there is a wealth of information on TB-HIV co-infection among settled populations in Africa and elsewhere, to our knowledge, there are no published reports on TB-HIV co-infection from pastoral communities. In this study, we report the prevalence of TB, HIV and TB-HIV co-infection among pulmonary TB suspects in the Afar Regional State of Ethiopia. DESIGN: In a cross-sectional study design, 325 pulmonary TB suspects were included from five health facilities. Three sputum samples (spot-morning-spot) were collected from each participant. Sputum samples were examined for the presence of acid fast bacilli using Ziehl-Neelsen staining method, and culture was done on the remaining sputum samples. Participants were interviewed and HIV tested. RESULTS: Of the 325 pulmonary TB suspects, 44 (13.5%) were smear positive, and 105 (32.3%) were culture positive. Among smear-positive patients, five were culture negative and, therefore, a total of 110 (33.8%) suspects were bacteriologically confirmed pulmonary TB patients. Out of 287 pulmonary TB suspects who were tested for HIV infection, 82 (28.6%) were HIV positive. A significantly higher proportion of bacteriologically confirmed pulmonary TB patients [40 (40.4%)] were HIV co-infected compared with patients without bacteriological evidence for pulmonary TB [42 (22.3%)]. However, among ethnic Afar pastoralists, HIV infections in smear- and/or culture-negative pulmonary TB suspects [7 (7.6%)] and bacteriologically confirmed pulmonary TB patients [4 (11.8%)] were comparable. On multivariable logistic regression analysis, Afar ethnicity was independently associated with low HIV infection [OR=0.16 (95% CI: 0.07-0.37)], whereas literacy was independently associated with higher HIV infection [OR=2.21 (95% CI: 1.05-4.64)]. CONCLUSIONS: Although the overall prevalence of TB-HIV co-infection in the current study is high, ethnic Afars had significantly lower HIV infection both in suspects as well as TB patients. The data suggest that the prevalence of HIV infection among Afar pastoralists is probably low. However, population-based prevalence studies are needed to substantiate our findings.

Lipoarabinomannan-specific TNF-α and IFN-γ as markers of protective immunity against tuberculosis: a cohort study in an endemic setting.

Lipoarabinomannan (LAM) is a virulent factor used for entry and survival of Mycobacterium tuberculosis (Mtb) in macrophages. Although the role of LAM for the diagnosis of tuberculosis (TB) has been extensively investigated, its cytokine response during natural Mtb infection in humans is largely unknown. In this study, LAM-specific IFN-γ, TNF-α, and IL-10 levels following whole blood assay were measured in untreated pulmonary TB patients, their contacts and community controls at baseline. In treated patients and contacts, cytokines were also measured at 6 and 12 months. At entry, 52.8% and 74.8% of controls and contacts were QFT-GIT positive, respectively. At baseline, untreated TB patients and contacts had significantly lower IFN-γ and TNF-α response compared to community controls (p < 0.0001). Besides, untreated patients had significantly higher TNF-α and IL-10 response compared to their contacts (p < 0.0001). At 6 months, contacts and treated TB patients had significantly increased INF-γ and TNF-α response (p < 0.0001). In TB patients, IFN-γ increased 10-fold following chemotherapy suggesting its potential role for treatment monitoring. The data suggests that LAM might have an anti-inflammatory effect during clinical TB and early Mtb infection. The data also suggests that LAM-induced IFN-γ and TNF-α could be used as biomarkers of protective immunity.

Prevalence and correlates of anemia among HIV infected patients on highly active anti-retroviral therapy at Zewditu Memorial Hospital, Ethiopia.

BACKGROUND: Ethiopia is one of the most seriously HIV affected countries in Sub-Saharan Africa. Anemia is a known predictor of disease progression and death among HIV infected patients. In this study, we investigated the magnitude and correlates of anemia among HIV infected patients receiving HAART at a referral hospital in Ethiopia. METHODS: A retrospective cohort study was conducted from November 2011 to February 2012 in Zewditu Memorial Hospital, Addis Ababa, Ethiopia. Records of 1061 patients on HAART were selected using simple random sampling technique. Socio-demographic and clinical characteristics of the study patients were collected using standardized data extraction instrument. Data were analyzed using STATA version 11.0. Odds ratios with 95% confidence intervals were used to quantify the strength of association between anemia and its potential predictors. RESULTS: The prevalence of anemia at baseline was 42.9%. However, the prevalence significantly decreased to 20.9% at 6 months (p < 0.001) and to 14.3% at 12 months (p = 0.001) after HAART initiation. At baseline, male sex (AOR = 1.55; 95% CI: 1.18-2.03), clinical stage III/IV (AOR = 2.03; 95% CI: 1.45-2.83) and TB co-infection (AOR = 1.52; 95% CI: 1.08-2.13) were independently associated with the odds of being anemic. After 6 months of HAART, male sex (AOR = 1.59; 95% CI: 1.13-2.23), baseline anemia (AOR = 2.38; 95% CI: 1.71-3.33) and TDF-based HAART (AOR = 2.87; 95% CI: 1.80-4.60) were independently associated with the odds of being anemic. Besides, anemia was independently associated with older age at 6 months. After 12 months of HAART, baseline anemia (AOR = 2.01; 95% CI: 1.36-2.97), age group 25-34 years (AOR = 5.92; 95% CI: 1.39-25.15), age group 45-54 years (AOR = 4.78; 95% CI: 1.07-21.36), CD4 count below 200 cells/mm(3) (AOR = 2.15; 95% CI: 1.21-3.82) and 200-350 cells/mm(3) (AOR = 1.91; 95% CI: 1.13-3.25) were independently associated with the odds of being anemic. CONCLUSIONS: Although a remarkable reduction in the prevalence of anemia was observed following initiation of HAART, a significant proportion of HIV patients remained anemic after 12 months of HAART suggesting the need for routine screening and proper treatment of anemia to mitigate its adverse effects.

Prevalence of smear positive pulmonary tuberculosis among outpatients presenting with cough of any duration in Shashogo Woreda, Southern Ethiopia.

BACKGROUND: Excluding patients with cough less than two weeks from screening for TB which is the current practice of TB control program in Ethiopia may result in delayed diagnosis thereby increasing transmission risk to others. The current study aimed to determine the prevalence of smear positive pulmonary tuberculosis among patients presenting with cough to four health centers in Shashogo woreda, Southern Ethiopia. METHODS: A cross sectional study was conducted in four health centers in Shashogo Woreda, between November 2011 and March 2012. Four-hundred and sixty one patients aged five years and above attending the outpatient clinics and reporting cough of any duration were screened for pulmonary TB using smear microscopy. During data analysis, patients were classified by duration of cough with the cut-off of two weeks. Stata version 11 was used for data analysis. RESULTS: A total of 299 patients with cough of two or more weeks and 162 patients with cough less than 2 weeks were recruited. The overall prevalence of smear positive pulmonary TB was 4.6% (95% CI: 2.6% to 7.7%). The prevalence of smear positive pulmonary TB among patients with cough lasting two or more weeks was significantly higher compared to those patients with cough lasting less than two weeks (6.0% versus 1.9%; p = 0.04). CONCLUSION: Although the prevalence of smear positive pulmonary TB among patients with cough less than 2 weeks was low, considering the contribution of delayed diagnosis for continued transmission of TB, screening patients with cough less than 2 weeks might be considered for TB control. A multi-site study with large sample size is needed to substantiate the current findings.

Pro- and anti-inflammatory cytokines against Rv2031 are elevated during latent tuberculosis: a study in cohorts of tuberculosis patients, household contacts and community controls in an endemic setting.

Tuberculosis (TB) is among the leading causes of morbidity and mortality. The causative agent, Mycobacterium tuberculosis (Mtb), has evolved virulent factors for entry, survival, multiplication and immune evasion. Rv2031 (also called alpha crystallin, hspX, 16-kDa antigen), one of the most immunogenic latency antigens, is believed to play a key role in long-term viability of Mtb. Here, we report the dynamics of pro-inflammatory (IFN-γ, TNF-α) and anti-inflammatory (IL-10) cytokines against Rv2031 using whole blood assay in human cohorts in a TB endemic setting. Cytokine responses to ESAT-6-CFP-10 were also measured for comparison. Blood samples were collected from smear positive pulmonary TB patients and their contacts at baseline, 6 and 12 months, and from community controls at entry. At baseline, 54.4% of controls and 73.2% of contacts were QFT-GIT test positive. Baseline IFN-γ, TNF-α and IL-10 responses to Rv2031 were significantly higher in controls compared to contacts and untreated patients (p<0.001). Furthermore, untreated patients had significantly higher TNF-α and IL-10 responses to Rv2031 compared to contacts (p<0.001). In contacts and treated patients, IFN-γ, TNF-α and IL-10 responses to Rv2031 significantly increased over 12 months (p<0.0001) and became comparable with the corresponding levels in controls. There was a positive and significant correlation between Rv2031 and ESAT-6-CFP-10 specific cytokine responses in each study group. The fact that the levels of IFN-γ, TNF-α and IL-10 against Rv2031 were highest during latent TB infection may indicate their potential as markers of protection against TB. Taken together, the findings of this study suggest the potential of IFN-γ, TNF-α and IL-10 against Rv2031 as biomarkers of the host response to Mtb during convalescence from, and the absence of, active tuberculosis.

Prevalence of malaria among acute febrile patients clinically suspected of having malaria in the Zeway Health Center, Ethiopia.

Malaria diagnosis is a common challenge in developing countries with limited diagnostic services. Common febrile illnesses were assessed in 280 malaria-suspected patients, and each case was subjected to clinical and laboratory examinations for malaria, relapsing fever, typhoid fever, typhus, and brucellosis. Data were entered and analyzed using Epi Info version 3.1 software. Malaria accounted for 17% (CI, 12.6-21.4%) of febrile illnesses. The remaining cases were associated with typhoid fever (18.5%; CI, 13.95-23.05%), typhus (17.8%; CI, 13.32-22.28%), brucellosis (1%; CI, -0.17-2.17%), relapsing fever (2%; CI, 0.36-3.64%), and unknown causes (44%). Approximately 7% of patients had coinfections, and 2% of patients treated as monoinfections. Approximately 1.4% of the nonmalarial patients received antimalarial treatment. The sensitivity and specificity of the CareStart Pf/pan rapid diagnostic tests in comparison with those of microscopy were 100% and 91%, respectively, with positive- and negative-predictive values of 94% and 100%, respectively. Compared with microscopy, the positive-predictive value of each malaria symptom was much lower than that of the symptoms combined: fever, 17%; sweating, 30%; headache, 18%; general body ache, 22%; loss of appetite, 21%. The study findings revealed a high proportion of nonmalarial illnesses were clinically categorized as malaria. Parasite-based diagnosis is recommended for the management of malarial and nonmalarial cases.

QuantiFERON-TB Gold In-Tube test conversions and reversions among tuberculosis patients and their household contacts in Addis Ababa: a one year follow-up study.

BACKGROUND: QuantiFERON-TB Gold In-Tube® (QFT-GIT) test is used for the diagnosis of latent tuberculosis (TB) infection. Besides, QFT-GIT test could allow tracking changes in immune response among TB patients and their contacts. In high TB burden settings, reports on QFT-GIT conversions and reversions among TB patients and their contacts are limited. As part of a major project to study immune responses to TB infection, we investigated QFT-GIT test conversions and reversions among smear positive pulmonary TB patients and their household contacts over 12 months. METHODS: We followed a total of 107 HIV negative participants (33 patients and 74 contacts) in Addis Ababa. We did QFT-GIT test at baseline and 12 months later according to the manufacturer's instructions. RESULTS: At baseline, 25/33 (75.8%) of the patients and 50/74 (67.6%) of the contacts were QFT-GIT positive. At 12 months, 2 more patients (1 test negative and 1 indeterminate) became test positive. Besides, 11/24 (45.8%) test negative contacts became positive. Only one patient and one contact who were test positive at baseline became test negative 12 months later. At 12 months, the proportions of QFT-GIT test positives for patients and contacts were, therefore, 78.8% and 81.1%, respectively. Among contacts, the proportion of QFT-GIT test positives at 12 months was significantly higher compared to the corresponding proportion at baseline (McNemar, p = 0.006); similarly, the median IFN-γ response significantly increased at 12 months compared with the baseline level (Wilcoxon matched-pairs signed rank test, p = 0.01). Patients, however, had comparable median IFN-γ levels at baseline and 12 months later (p = 0.56). CONCLUSION: Nearly half of QFT-GIT negative household contacts at baseline became positive at 12 months. This suggests that repeated screening of QFT-GIT negative contacts may be needed for epidemiological studies and interventions of latent TB in an endemic setting. A large longitudinal study may be needed to confirm our observations.

Strain diversity of Mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Afar pastoral region of Ethiopia.

Data on genotypic diversity of Mycobacterium tuberculosis complex (MTBC) is important to understand its epidemiology, human adaptation, clinical phenotypes, and drug resistance. This study aimed to characterize MTBC clinical isolates circulating in a predominantly pastoralist area in Ethiopia, a country where tuberculosis is the second leading cause of mortality. Culture of sputum samples collected from a total of 325 pulmonary TB suspects was done to isolate MTBC. Spoligotyping was used to characterize 105 isolates from culture positive slopes and the result was compared with an international database. Forty-four spoligotype patterns were observed to correspond to 35 shared-types (SITs) containing 96 isolates and 9 orphan patterns; 27 SITs containing 83 isolates matched a preexisting shared-type in the database, whereas 8 SITs (n = 13 isolates) were newly created. A total of 19 SITs containing 80 isolates were clustered within this study (overall clustering of 76.19%). Three dominant lineages (T, CAS, and Manu) accounted for 76.19% of the isolates. SIT149/T3-ETH was one of the two most dominant sublineages. Unlike previous reports, we show that Manu lineage strains not only constitute a dominant lineage, but are also associated with HIV infection in Afar region of Ethiopia. The high level of clustering suggests the presence of recent transmission that should be further studied using additional genotyping markers.

Childhood tuberculosis and its treatment outcomes in Addis Ababa: a 5-years retrospective study.

BACKGROUND: Tuberculosis (TB) remains a significant public health problem leading to high morbidity and mortality both in adults and children. Reports on childhood TB and its treatment outcome are limited. In this retrospective study, we analyzed the epidemiology and treatment outcomes of TB among children in Addis Ababa. METHODS: Children registered for TB treatment over 5 years (2007 to 2011) were included in the analysis. Demographic and clinical data including treatment outcomes were extracted from TB unit registers of 23 health centers in Addis Ababa. Multivariate logistic regression was used to identify predictors of poor treatment outcomes. RESULTS: Among 41,254 TB patients registered for treatment at the 23 health centers, 2708 (6.6%) were children. Among children with TB, the proportions of smear positive PTB, smear negative PTB and EPTB were 9.6%, 43.0% and 47.4%, respectively. Treatment outcomes were documented for 95.2% of children of whom 85.5% were successfully treated while rates of mortality and defaulting from treatment were 3.3% and 3.8%, respectively. The proportion of children with TB tested for HIV reached 88.3% during the final year of the study period compared to only 3.9% at the beginning of the study period. Mortality was significantly higher among under-five children (p < 0.001) and those with HIV co-infection (p < 0.001). On multivariate logistic regression, children 5-9 years [AOR = 2.50 (95% CI 1.67-3.74)] and 10-14 years [AOR = 2.70 (95% CI 1.86-3.91)] had a significantly higher successful treatment outcomes. On the other hand, smear positive PTB [AOR = 0.44 (95% CI 0.27-0.73), HIV co-infection (AOR = 0.49(95% CI 0.30-0.80)] and unknown HIV sero-status [AOR = 0.60 (95% CI 0.42-0.86)] were predictors of poor treatment outcomes. CONCLUSION: The proportion of childhood TB in this study is lower than the national estimate. The overall treatment success rate has met the WHO target. Nonetheless, younger children (< 5 years), children with smear positive PTB and those with HIV co-infection need special attention to reduce poor treatment outcomes among children in the study area.

Adherence to Antiretroviral Therapy and associated factors among HIV infected children in Ethiopia: unannounced home-based pill count versus caregivers' report.

BACKGROUND: The introduction of Antiretroviral Therapy (ART) has brought a remarkable reduction in HIV-related mortality and morbidity both in adults and children living with HIV/AIDS. Adherence to ART is the key to the successful treatment of patients as well as containment of drug resistance. Studies based on caregivers' report have shown that adherence to ART among children is generally good. However, subjective methods such as caregivers' report are known to overestimate the level of adherence. This study determined the rate of adherence and its predictors using unannounced home-based pill count and compared the result with caregivers' report in a tertiary referral hospital in Ethiopia. METHODS: A cross-sectional study was conducted between December 1, 2011 and January 30, 2012. The study participants were 210 children on ART and their caregivers attending pediatric ART clinic of Tikur Anbessa Hospital (TAH), Addis Ababa University. Caregivers were interviewed at the ART clinic using a structured questionnaire. Then, unannounced home-based pill count was done 7 days after the interview. RESULTS: Caregiver-reported adherence in the past 7 days prior to interview was 93.3%. Estimated adherence using unannounced home-based pill count was found, however, to be 34.8%. On multivariate logistic regression model, children with married [aOR = 7.85 (95% CI: 2.11,29.13)] and widowed/divorced [aOR = 7.14 (95% CI: 2.00,25.46)] caregivers, those who were not aware of their HIV sero-status [aOR = 2.35 (95% CI:1.09, 5.06)], and those with baseline WHO clinical stage III/IV [OR = 3.18 (95% CI: 1.21, 8.40] were more likely to adhere to their ART treatment. On the other hand, children on d4T/3Tc/EFV combination [OR = 0.10 (95% CI: 0.02, 0.53)] were less likely to adhere to their treatment. Caregivers' forgetfulness and child refusal to take medication were reported as the major reasons for missing doses. CONCLUSION: The level of adherence based on unannounced home-based pill count was unacceptably low. Interventions are urgently needed to improve adherence to ART among children at TAH. Besides, a longitudinal study measuring adherence combined with clinical parameters (viral load and CD4 count) is needed to identify a simple and reliable measure of adherence in the study area.

Efficacy of Praziquantel against Schistosoma haematobium in Dulshatalo village, western Ethiopia.

BACKGROUND: Praziquantel (PZQ) is the drug of choice for treatment of all human schistosomes. It is used in population based targeted or mass deworming strategies in several countries. The effect of PZQ on S. hematobium has not been studied in Ethiopia. The objective of this study was to determine the efficacy of PZQ against S. haematobium in Dulshatalo village, western Ethiopia. METHODS: A prospective study was conducted from October to December, 2007. Urine samples from 341 residents were collected and screened for haematuria and proteinuria using urinalysis dipstick. S. haematobium eggs were detected and quantified using filtration techniques. The participants who were positive for haematuria were treated with a standard dose of PZQ (40 mg/kg). Data on pre and 24 hours post treatment symptoms were collected via questionnaire. Urine samples were also collected 7 weeks after treatment and examined to assess the cure and the egg reduction rates. RESULTS: The prevalence of S. haematobium among the study participants was 57.8% (197/341). Haematuria was detected in 234 (68.6%) of the study participants. For PZQ efficacy asessment, 152 of the treated participants were considered. The presence of S. haemetaobium eggs showed statistically significant association (p < 0.05) with haematuria and proteinuria. Seven weeks post treatment, the extent of haematuria and proteinuria decreased from 100% to 40.8% and 94.07% to 48.7%, respectively. The cure and the parasitological egg reduction rates seven weeks post treatment were 86% and 85%, respectively. Post treatment symptoms revealed a wide range of side effects including straining, abdominal pain, nausea and headache. CONCLUSIONS: There were marked cure and egg reduction rates, together with mild and short lived side effects of PZQ for treatment of S. haematobium, in this study.

Assessment of antibacterial drug exposure patterns of patient encounters seen by different categories of prescribers at health institutions in Bahir Dar, Ethiopia.

BACKGROUND: Understanding of existing antibacterial drug prescribing patterns is a pre-requisite for further investigation of potential determinants of irrational prescribing, if any, thereby looking for solutions would be easier. OBJECTIVE: This study was conducted to assess antibacterial prescription patterns of different health professionals working at general outpatient clinics of different health institutions. METHODS: In this cross-sectional study, a total of 1558 prescriptions of patient encounters, were collected from four clusters of prescribers randomly selected from 11 public and 15 private health institutions in Bahir Dar town and its environs, North West Ethiopia. RESULTS: A significant proportion of patient encounters were exposed to at least one antibacterial drug with percentage of encounters to whom antibacterial(s) prescribed was 64.5%. Multiple antibacterial drug exposure was minimal (7.8%) with a maximum of 3 antibacterial drugs per encounter. The study showed that patients at pediatric age group were more likely to receive an antibacterial drug than adult counter parts (70.3% vs 62.8%, p = 0.038, OR = 1.33). On the other hand, there were no statistically significant differences in the antibacterial exposure patterns of patients seen by prescribers of shorter pre-service training (health assistants and nurses) and those with longer duration (health officers and general practitioners) and also between patients seen at public and private health institutions. CONCLUSIONS: This study indicates that a significant proportion of patient encounters were exposed to antibacterial drugs. The actual determinants of the existing patterns should be further investigated in order to arrive at clear and feasible strategies to promote rational antibacterial drug prescribing practices.